Water Resources Research Act Program

Details for Project ID 2009TX329B

In Situ Groundwater Arsenic Removal using Iron Oxide Coated Sand

Institute: Texas
Year Established: 2009 Start Date: 2009-03-01 End Date: 2010-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $10,000

Principal Investigators: Hongxu Yu, Yongheng Huang

Project Summary: Iron oxide-bearing minerals have long been recognized as an effective reactive media for arsenic (As) remediation. In this project, we propose to use a unique iron oxide coating technique we invented to develop a cost-effective in situ treatment technique for removing arsenic from contaminated groundwater. To in situ emplace iron oxide coatings on soil particles, ferrous salt and sodium hypochlorite solutions will be periodically injected into soil matrix following a special designed injection scheme. The resulting adsorption, diffusion, and redox reaction could continuously deposit large quantities of ferric oxide onto the surface of soil particles, thus creating a constantly-refreshed reactive surface for continuously adsorption and co-precipitation of arsenic and other heavy metals. Our bench-scale column tests have shown that the technique could rapidly and sustainably remove arsenic from synthetic water spiked with arsenic. To further develop this technique for groundwater arsenic treatment, we propose to conduct scale-up column tests using real groundwater to further elucidate the mechanism and kinetics of arsenic removal and to develop a model to predict the performance of the system.